I've never used any OS other than windows, but have decided to try ubuntu 14.04. I have 30GB of free space on the SSD and 200GB on the HDD. Now what partitions should I create?

I really have no idea how the file system in ubuntu works. I have been reading a lot and got a lot of conflicting information.

In Windows I use the SSD for the OS and smaller programs and the HDD for bigger programs, games and other large files. I want to do it similarly for ubuntu. I also want to be able to exchange files between Windows and ubuntu without them interfering.

So obviously /root should go on the SSD, as that takes most advantage of the SSD's speed? How big should /root be?

I seem to also need a /home partition. Where should I put that, if some of my programs should go on the SSD and some on the HDD? Is it possible to "split" /home between both? Or can I install programs outside of home? If yes, what would the disadvantages of that be? Should I install programs on home at all or is it simply the ubuntu equivalent to Windows' Appdata, and programs themselves should go somewhere completely different?

Lastly, what about swap? A lot of conflicting information on that. Some say you don't need it at all, some say it should be a fixed size, some say it needs to be more, the more ram you have. I have 8GB ram, which I almost never fully use and I do not plan on ever hibernating.

So as I understand it, swap is basically a reserve for when your ram is all in use. What's the worst thing that can happen, if I don't have swap? And why would it need to be larger if I have MORE ram? Shouldn't I need LESS "reserve", if I already have more "actual ram"? Also, why do I need an extra partition anyway? AFAIK windows simply uses a normal file pagefile.sys on the normal partition, which can easily be changed in size. What's the advantage of having an extra partition?

Also, if I do need swap, where should I put it? Some sources they it wears out the SSD much more quickly, others say that won't be a problem for over 20 years and swap benefits hugely from being on the SSD.

3 Answers
3

/root is not the directory where the system is installed. It's the home directory of the "allmighty system administrator", known as root user (username is root, user ID=0)

What you're probably thinking of is the root directory. Windows has multiple root directories, C:, D: and so on. Most other OS's, including Linux, only got one root directory: /. The system gets installed into various subfolders of it: /bin, /boot, /usr, ...

No program gets installed into /home. This is where the users have there own directories, e.g. /home/sebastian/ for me. This is where you store your own stuff (like C:\Users\username\ on Win 7 or C:\Documents and Settings\username\ on XP). Programs only store there configuration stuff in here. Most programs get installed somewhere into /usr.

What I'm now writing is opinion based and everyone got another opinion on it. I can't recommend you any scenario, you have to choose:

Scenario 1 (no swap, you'll have to live with 8GB of RAM (should be enough)):

Use the SSD to install the core system in (mountpoint /)

Because it's only 30GB, you should put /home to the HDD

Scenario 2 (8GB of SWAP):

Create a 8GiB swap partition on the SSD, use the rest for your core system (/)

Create a partition on the HDD for /home

Create another partition for /usr

I'd recommend to the HDD 100GiB for /home and 100 for /usr, but this is up to you

Thanks for clearing up some of my misconceptions. I falsely assumed /root and / are the same thing. I now ended up putting / on the SSD and /home on the HDD, as well as 10GB swap on the HDD, just in case I need it, as space isn't as sparse there.
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HuchickutMay 19 '14 at 8:57

I`ve been a dual-boot-er for almost 4 years now and I have not yet seen Ubuntu needing and taking advantage of SSD speed. So I recommend installing Ubuntu on the HDD, leaving the SSD to deal with Windows for data security reasons.

You will need a minimum of 2 partitions:

1) an ext (ext4 recommended) that will be /. In this partition you will have the /home, /root and everything.

2) a swap partition. In the old days, it was recommended to have the swap double the RAM ammount. Nowadays, you no longer need that. Just make a 8GB swap at the end ogf the HDD.

As for the / partition, the size depends on what you want to do. My / is 30GB.

The programs you install will be in the / partition.

So:

1) Create a ~35GB primary ext4 partition on the HDD (preferably at the beginning of the partition table, but if not, at the end will do), with the mount point: /

2) Create a 8GB partition on the HDD (preferably at the end of the partition table) and select "use as: Swap area"

You can create a 30 GB partition on your SSD for Ubuntu, but I think you mean you have 30 GB of free space on Windows, so if you create a 30 GB partition Windows will have no free space left, which will cause problems for Windows.

So you could create a 20 GB partition for Ubuntu (Ubuntu partitions can't be used by Windows) on your SSD. You'll use mount point / for this one, which is basically the root FS. All your applications will be stored here too if you use Ubuntu's package manager. This shouldn't be a problem as most programs are not so big and you've ~10 GB of free space (Ubuntu will preserve some space for its journal and /root directory).

If you've a really big application you can compile it yourself in your home/bin directory. Or if you use Steam for example you can choose to store your library in your home directory.

Then create a partition on your HDD for /home. This is the partition where all your personal files (like documents, downloads, videos, settings) will be stored (like the Users directory in Windows). As this will probably contain the "big data" it's a good idea to create this partition on your HDD.

The swap partition is the same as the swap file in Windows. It's virtual RAM. If you have enough RAM and don't need hibernation, you don't need it. If you ever need it, you can always create a swap partition after installing Ubuntu or you can create a swap file.

Also, both Windows and Ubuntu can read and write on NTFS (but you can't install Ubuntu on NTFS). So if you want to share files between the two, create (or use an existing) a NTFS partition.